diff --git a/backends/imgui_impl_win32.cpp b/backends/imgui_impl_win32.cpp index 363e016d..c347a871 100644 --- a/backends/imgui_impl_win32.cpp +++ b/backends/imgui_impl_win32.cpp @@ -817,3 +817,45 @@ float ImGui_ImplWin32_GetDpiScaleForHwnd(void* hwnd) HMONITOR monitor = ::MonitorFromWindow((HWND)hwnd, MONITOR_DEFAULTTONEAREST); return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor); } + +//--------------------------------------------------------------------------------------------------------- +// Transparency related helpers (optional) +//-------------------------------------------------------------------------------------------------------- + +#if defined(_MSC_VER) +#pragma comment(lib, "dwmapi") // Link with dwmapi.lib. MinGW will require linking with '-ldwmapi' +#endif + +// [experimental] +// Borrowed from GLFW's function updateFramebufferTransparency() in src/win32_window.c +// (the Dwm* functions are Vista era functions but we are borrowing logic from GLFW) +void ImGui_ImplWin32_EnableAlphaCompositing(void* hwnd) +{ + if (!_IsWindowsVistaOrGreater()) + return; + + BOOL composition; + if (FAILED(::DwmIsCompositionEnabled(&composition)) || !composition) + return; + + BOOL opaque; + DWORD color; + if (_IsWindows8OrGreater() || (SUCCEEDED(::DwmGetColorizationColor(&color, &opaque)) && !opaque)) + { + HRGN region = ::CreateRectRgn(0, 0, -1, -1); + DWM_BLURBEHIND bb = {}; + bb.dwFlags = DWM_BB_ENABLE | DWM_BB_BLURREGION; + bb.hRgnBlur = region; + bb.fEnable = TRUE; + ::DwmEnableBlurBehindWindow((HWND)hwnd, &bb); + ::DeleteObject(region); + } + else + { + DWM_BLURBEHIND bb = {}; + bb.dwFlags = DWM_BB_ENABLE; + ::DwmEnableBlurBehindWindow((HWND)hwnd, &bb); + } +} + +//---------------------------------------------------------------------------------------------------------